Strange Network Requirement

[visitor68]

Had a client tell me today of a bizarre requirement...

He wants to build a leaf/spine fabric with NO Oversubscription at all between leaf and spine...So, imagine a 64-port 10G switch as a leaf...he wants to use 32 for servers and 32 for uplinks...he wants to do this in a TRILL-enabled fabric so that he doesnt have to worry about scaling uplinks and LAGing them...

He says he wants to do this because he wants "full bi-sectional bandwidth," which to me is a misappropriation of the term. Full bi-sectional bandwidth refers to the uplink BW between leaf and spine in which no uplink ports are blocked by STP. He interprets "full bi-sectional BW" to mean a 1:1 subscription between leaf and spine.

Has anyone heard of somethign so strange?

Thanks!

[Leo Laohoo]

"full bi-sectional bandwidth,"

I dunno.  Sounds like "full bi-directional bandwidth" which, in my humble opinion, means FULL DUPLEX.

[Danilo Dy]

Here is the link to an article about STP and bisectional bandwidth http://etherealmind.com/bisectional-bandwidth-l2mp-trill-bridges-design-value/

[visitor68]

I know what bi-sectional BW is - I am interested in hearing people's thoughts regarding the bizarre requirement I articulate din the first paragraph!

He wants to build a leaf/spine fabric with NO Oversubscription at all between leaf and spine...So, imagine a 64-port 10G switch as a leaf...he wants to use 32 for servers and 32 for uplinks...he wants to do this in a TRILL-enabled fabric so that he doesnt have to worry about scaling uplinks and LAGing them...

[siddhartham · Accepted solution]

I never heard about that kind of requirement and you are right it looks like he misinterpreted the meaning of bisectional bandwidth.